#import <Foundation/Foundation.h>

@interface XYZPerson : NSObject

@property NSString *firstName;
@property NSString *lastName;
@property NSDate *birth;

+ (void) person;
- (void) sayHello;
@end

@implementation XYZPerson

- (void) sayHello {
  NSLog(@"Hello World!");
}
@end

int main(int argc, char const* argv[]) {
  XYZPerson * person = [[XYZPerson alloc] init];

  [person sayHello];
  return 0;
}